Canine Cataract Research Articles

AI-driven canine cataract detection: a machine learning approach using support vector machine

ABSTRACT The pivotal role of the Support Vector Machine becomes evident in addressing the impact of aging and genetics on canine cataract development. Timely detection, crucial for preventing illness in dogs, is facilitated by Artificial Intelligence. This proves especially beneficial for veterinarians grappling with detection challenges. Within the realm of Artificial Intelligence, the subset of Machine Learning emerges as a promising avenue for tackling intricate tasks. The current study introduces a model for grading canine cataracts through images captured on standard mobile phone cameras. Notably, the proposed system centers around harnessing the power of the Support Vector Machine, a potent Machine Learning algorithm tailored for classifying (grading) cataracts based on images. Rigorous evaluation, employing K-fold Cross-validation, validates the images’ reliability. Both binary-class and multi-class experimentation contribute to the dataset. Impressively, the accuracy rates for the trained classification model stand at 83% (without Cross-validation) and 81% (with Cross-validation for K = 10), underscoring the robustness of the approach.

Refractive error of canine cataract patients following implantation with three types of intraocular lenses.

To evaluate refractive state outcomes following phacoemulsification and implantation of 3 different intraocular lenses (IOLs). A prospective, randomized, controlled study was conducted on 43 client-owned dogs undergoing phacoemulsification with IOL implantation. Eyes were randomized to receive either an-vision Fo-X (n = 26), an-vision MD8 (18), or I-MED I-LENS (24) IOL. Refraction was measured 1 week, 1 month, and 3 months postoperatively using streak retinoscopy by 2 examiners masked to each other's results. Postoperative refractive outcomes were highly correlated and not significantly different between 2 examiners for all time points (r = 0.97, 0.98, and 1.00; P = .76, .94, and .98, respectively). One week postoperatively, the refractive errors (mean ± SD) for Fo-X, MD8, and I-LENS were -0.14 ± 2.02 diopters (D), 0.97 ± 2.01 D, and 0.15 ± 2.55 D, respectively. One month postoperatively, the refractive errors were 0.35 ± 2.04 D, 0.06 ± 2.41 D, and -0.82 ± 2.20 D, respectively. Three months postoperatively, the refractive errors were -0.16 ± 2.67 D, 1.60 ± 2.99 D, and 0.59 ± 1.51 D, respectively. There were no significant differences in refractive error outcomes between Fo-X, MD8, and I-LENS at 1 week, 1 month, and 3 months postoperatively (P = .16; F(df=2,66)- = 1.89). However, the Fo-X was the only IOL to yield nearly emmetropic outcomes (±0.50 D) at all 3 time points. The postoperative refractive states of dogs were not statistically different when comparing 3 types of IOLs at 3 postoperative time points, though the Fo-X was the only IOL to yield nearly emmetropic outcomes at all 3 time points.

The use of sub-Tenon's anesthesia versus a low-dose neuromuscular blockade for canine cataract surgery: Acomparative study of 224 eyes.

Assess the utility of a Sub-Tenon's anesthesia (STA) protocol to provide suitable operating conditions for canine cataract surgery and compare it to an alternative low-dose neuromuscular blockade (LD-NMB) protocol used for canine cataract surgery. Clinical study of dog eyes undergoing cataract surgery with either an STA or LD-NMB protocol. While intraoperative vitreal expansion scores and intraoperative complications were collected prospectively, globe position, intraocular pressure, return of vision, and postoperative complications were collected retrospectively. Statistical testing was used to compare results between the STA and the LD-NMB groups for the data available. A total of 224 eyes from 126 dogs were assessed, with 133/224 (59.4%) eyes from 99/126 (78.6%) dogs receiving STA and 91/124 (40.6%) eyes from 72/126 (57.1%) dogs receiving LD-NMB. Forty-five of these dogs (45/126; 37.7%) received STA for one eye and LD-NMB for the other eye. There was no significant change in intraocular pressure measurements following STA administration. This was not measured for the LD-NMB group. The globe achieved a central position in 110/133 (82.7%) of eyes that received STA. This was not measured for the LD-NMB group. Intraoperative vitreal expansion scores were slightly higher in STA-treated eyes compared to LD-NMB-treated eyes. The intraoperative complication rate for STA-treated eyes was higher (73/133; 54.8%) compared to NMB-treated eyes (12/91; 13.2%). The most common intraoperative complication for STA was chemosis (64/133; 48.1%), the risk of which increased with an increase in the volume of local anesthetic injected. The post-operative complication rate was higher in STA-treated eyes (28/133; 21.1%) compared to NMB-treated eyes (16/91; 17.6%). Post-operative corneal ulceration was the most common postoperative complication in STA-treated eyes (6/133; 4.5%). The STA protocol described resulted in suitable operating conditions, but more intraoperative and postoperative complications compared to the LD-NMB protocol. Despite these complications, the STA protocol did not cause a significant deleterious impact on post-operative outcomes as defined in the present study.

Prevalence and outcome of lens capsule disruption in routine canine cataract surgery: A retrospective study of 520 eyes (2012-2019).

To investigate the prevalence and surgical outcome of lens capsule disruption (LCD) in dogs undergoing cataract removal. Medical records of 924 eyes undergoing phacoemulsification were analyzed retrospectively. Routine cataract surgeries with or without LCD were included. Any LCD other than routine anterior capsulorhexis was defined as LCD and classified according to location and etiology. Odds ratios (OR) were calculated for maintaining vision, implantation of an artificial intraocular lens (IOL), and enucleation. In total, 520 eyes were included. A LCD occurred in 145 eyes (27.8%; 145/520) and affected the posterior (85.5%; 124/145), anterior (6.2%; 9/145), and equatorial lens capsule (4.8%; 7/145) and at multiple locations (3.4%; 5/145). The etiology of the LCD was spontaneous preoperative in 41 eyes (28.3%; 41/145), accidental intraoperative in 57 eyes (39.3%; 57/145), and planned in 47 eyes (32.4%; 47/145). Disruption did not increase the odds of enucleation (OR = 1.48, 95% confidence interval [CI] 0.56-3.67; p = .36). The presence of LCD significantly increased the risk of losing vision 1 year post-operatively (OR = 8.17, 95% CI 1.41-84.93; p = .007) associated with retinal detachment. However, this was not present at 2 years follow-up or in PCCC cases at any time point. An IOL was implanted in 108 eyes (108/145; 75.2%) with LCD and in 45/47 (95.7%) eyes with a PCCC. Increased surgeon awareness of possible intraoperative, accidental LCDs is important, as LCDs were relatively common and associated with increased odds for vision loss after 1 year in the present study. A prospective study investigating the causes of intraoperative, accidental LCD is warranted.

Intraoperative management of axial posterior capsular opacities during cataract surgery in six dogs.

Posterior capsular opacification (PCO) is a cause of decreased vision after canine cataract surgery. PCO can appear in the months following surgery but can also be present at the time of surgery. To describe the intraoperative management of marked axial PCO during canine cataract surgery through a retrospective case series study of six cases. Six dogs (six eyes) with cataracts were included in this study. A complete ophthalmologic examination including electroretinography and ocular ultrasound was performed. After conventional phacoemulsification, a marked PCO obstructing the visual axis was found in five cases, previously diagnosed by ultrasound in the sixth. An axial posterior capsulorhexis (APC) was performed in all cases, before or after implantation of the intraocular lens (IOL). For the four cases implanted before APC, the posterior capsule (PC) was visualized either by positioning the IOL laterally in the bag with viscoelastic or through the optic of the implant. After perforation of the PC with a 30-Gauge needle, APC was initiated with Vannas curved scissors, then finalized with Utrata forceps to obtain a circular axial opening (3 mm diameter). In each case, a moderate anterior vitrectomy was performed through the APC (under the IOL when initially placed), then the IOL centered and the viscoelastic was removed. Six dogs (Beagle, German Shepherd, Cavalier King Carles, French pointing dog, American bully, Beagle Harrier) aged 11 to 94 months (mean 51.8) were included. The mean follow-up period was 15.5 months (range 10-22). Visual function with capsular axial transparency and well-centered IOL, without complications during the follow-up period, was preserved for each eye. APC combined with moderate anterior vitrectomy appears to be effective in the treatment of marked axial PCO obstructing the visual axis during canine cataract surgery.

Posterior lens capsule rupture in non‐diabetic canine cataracts: Pre‐operative, intra‐operative, and post‐operative findings

To describe clinical features of non-diabetic canine cataracts with presumed pre-existing posterior capsule rupture (PLCR) and their surgical outcomes. Clinical records of 497 non-diabetic canines that underwent elective cataract surgery were reviewed. Twelve canines met the inclusion criteria indicative of PLCR pre-dating surgery. The incidence of presumed pre-existing PLCR was 12/497 (2.4%). Cataracts included were unilateral in 10 out of 12 canines (83.3%) and bilateral in the remaining two (16.7%). Four eyes (28.6%) had clinically detectable pre-operative lens-induced uveitis. The mean age at cataract diagnosis for cases included was 6.6 years, and golden retrievers were the most common breed affected (28.6%). Phacoemulsification surgery was performed at a median time of 110 days (range 17-403 days) after presentation. Pre-existing PLCR was found intra-operatively as a large ellipse spanning the posterior capsule from equator to equator centrally in 12 eyes and peripherally in two eyes. The capsular defect in all eyes with PLCR incorporated a distinct "pseudo-capsule" preventing vitreal presentation and ruling out intraoperative surgeon rupture. Ten eyes (71.4%) received an intraocular lens implant (IOL), and 13 eyes (92.9%) maintained vision throughout a mean follow-up period of 12 months. Posterior lens capsule rupture of blunt trauma origin and associated cataract formation, as reported in humans, may also be an infrequent but distinct cause of some cases of non-diabetic canine cataracts. Medical management of phacolytic uveitis and delayed phacoemulsification surgery may be beneficial by allowing time for "pseudo-capsule" development, increasing the likelihood of IOL placement and improved visual outcomes.

Molecular and microbiological evidence of bacterial contamination of intraocular lenses commonly used in canine cataract surgery.

Inflammatory outcomes, including toxic anterior segment syndrome (TASS) and infectious endophthalmitis, are potentially painful, blinding complications following cataract surgery. In an in vitro pilot study, commercially available, sterile foldable intraocular lenses (IOLs) used during routine canine cataract surgery, and their packaging fluid were surveyed for the presence of bacterial DNA and/or viable (cultivable) bacteria. Swabs from IOLs and packaging fluid from three different veterinary manufacturers and three different production lots/manufacturer were collected for 16S ribosomal ribonucleic acid (rRNA) sequencing. Packaging fluid samples were collected for aerobic/capnophilic bacterial culture. Culture yielded one isolate, identified as Staphylococcus epidermidis. 16S rRNA sequencing revealed distinct brand-specific bacterial DNA profiles, conserved between IOLs and packaging fluid of all production lots within each manufacturer. The dominant taxonomy differentiating each manufacturer was annotated as Staphylococcus sp, and was a 100% match to S. epidermidis. Distinct mixtures of bacterial DNA are present and consistent in IOLs and packaging fluid depending on the manufacturer, and Staphylococcus is the dominant contributor to the bacterial DNA detected. Caralens products had a significantly lower amount of Staphylococcus spp. compared to Anvision and Dioptrix products.

Retrospective evaluation of pre-surgical electroretinography results in a mixed-breed canine population presented for cataract removal surgery.

Electroretinography (ERG) is used prior to cataract removal surgery to assess retinal function. We aimed to replicate and improve upon previous studies by performing a full ECVO protocol and by examining the retina post-surgery in all patients. One hundred twenty-seven eyes from 67 dogs were included in the study. A full ECVO protocol electroretinography, which includes extensive rod and cone analysis, was performed on all dogs presenting for cataract surgery. Our main findings were that amplitudes, but not implicit times of rod responses decreased with advanced cataracts. Amplitudes of the single flash rod and rod flicker responses were significantly lower in eyes with mature cataracts, and the former also decreased in hypermature cataracts. Cone flicker amplitude responses were also significantly lower in eyes with mature and hypermature cataracts. However, mixed single flash rod-cone and cone responses, with the exception of the mixed rod-cone a-wave amplitude in eyes with hypermature cataracts, were unaffected by cataract stage. The b-wave amplitude of the scotopic, mixed rod-cone, and photopic cone responses were affected by age and decreased by an average of 2.9, 7.5, and 1.5μV/year, retrospectively (p < 0.01). Lower ERG amplitudes in canine cataract patients may result from aging or the presence of advanced cataracts and may not indicate the presence of retinal disease.

The role of veterinary nurses in canine cataracts

Canine cataract formation is a commonly presented condition in first opinion practice. With the advancements in medical knowledge and the availability of surgical correction registered veterinary nurses are becoming increasing involved in their management and the education of owners. This article aims to discuss the aeitology of canine cataracts, the management options available and the role of veterinary nurses in these cases.

Retrospective evaluation of phacoemulsification and aspiration in 182 eyes: Visual outcomes and CDE-predictive value.

To determine the effect of cumulative dissipated energy (CDE) on complications and visual outcome following cataract surgery in dogs. Records of 182 canine eyes that had undergone cataract surgery. Retrospective medical record review was conducted on dogs that underwent unilateral or bilateral elective cataract surgery by a single surgeon. Preoperative variables such as age, cataract duration, and pre-existing conditions were recorded. Intraoperative variables such as intraocular lens (IOL) status, phacoemulsification time, average power, irrigation fluid volume, and CDE were recorded. Postoperative complications and visual status at last follow-up were compared to these variables. Eighty-six percent of dogs were visual in one or both eyes at last follow-up (LFU) examination. Median follow-up time was 186days postoperatively. Eyes that developed glaucoma had a significantly greater mean CDE (77.73±80.11) than eyes that did not develop glaucoma (49.21±38.93). Eyes that remained visual at the LFU examination had a significantly lower mean CDE (48.31±37.14) than eyes that were blind at LFU (82.05±82.73). Significantly lower mean CDEs were found in diabetic eyes, younger eyes, early-operated eyes (<1month duration), and eyes with preoperative lens-induced uveitis. Higher CDE may be associated with an increased risk of postoperative glaucoma and loss of vision in dogs. Cumulative dissipated energy may be a useful prognostic indicator for success of canine cataract surgery.

Study of Occurrence of Cataract and their Surgical Management in Dogs

Background: Present study investigated the occurrence of cataract in dogs presented to the Teaching Veterinary Clinical Complex (TVCC) and Department of Veterinary Surgery and Radiology under Odisha University of Agriculture and Technology, Bhubaneswar during a period of four months. During the study period, a total number of 3847 canine cases were registered at TVCC, out of which 23 cases registered under the RKVY project for different types of ophthalmic affections. There were only eight canine cataract cases with overall prevalence of 0.2% among total canines presented to TVCC and 34.78% of total canines presented with some sorts of ophthalmic affections. Methods: Menace reflex, pupillary light reflex, maze test, obstacle test, catoptrics test, Schirmer’s tear test (STT), Schiotz tonometry, Slit lamp bio microscopy and fundus examination -using indirect ophthalmoscope (IO) and fundus camera, were carried out in all the cases studied. Result: Occurrence of cataract was higher in Spitz (50%). Males had more incidences (62.5%) of cataract. The ages of the dogs were less than 10 years. B mode ultra-sonographic (USG) examination revealed increased echogenecity of lens in all cataract affected dogs while corneal opacification was found in two cases. Cataract was extracted by phaco-emulsification in three dogs and by small incision cataract surgery (SICS) technique in one dog.

Postoperative Complications after Phacoemulsification and Implantation of Foldable Acrylic Intraocular Lenses in Dogs

Background: Despite significant advances in canine cataract surgery over the years, many post-operative complications persist and reduces the success rate of phacoemulsification procedure. The aim of current study was to evaluate post-operative complications encountered till 90 days after bimanual phacoemulsification with implantation of different acrylic Intraocular Lenses.Methods: The study was conducted on 24 canine eyes. All the clinical cases were subjected to detailed ocular, ultrasonography and neuro-ophthalmic tests for ascertaining cataract and associated neuro-ophthalmic pathology. Dogs were divided in four groups with 6 eyes in each group and subjected to phacoemulsification procedure for removal of cataractous lens and implanted with square edge or round edge hydrophilic or hydrophobicintra ocular lenses.Result: Statistically non-significant (p£0.05) variations were found for all the post- operative complications among the groups. Within the groups initially higher values were recorded and on subsequent days a declining trend of varying degrees were observed. The corneal opacity was a major postoperative complication leading to failure to achieve vision with other coinciding neuro-ophthalmic conditions.

Characterization of postoperative "fibrin web" formation after canine cataract surgery.

To describe the occurrence and associated factors for "fibrin web" (FW) formation following phacoemulsification in dogs. A retrospective review of medical records of all dogs undergoing phacoemulsification (MU-Veterinary Health Center, 2014-2018) was conducted to associate FW formation with signalment, systemic co-morbidities, cataract stage, surgeon (resident vs faculty), phacoemulsification time, IOL, and intracameral injections including viscoelastic type. Both univariate and multivariate statistical analyses were performed to evaluate associations among variables with FW formation. Data from 398 eyes on 201 dogs were included; 4 left eyes (4 dogs) developed presumptive endophthalmitis and were excluded from further analysis. Forty-eight eyes did not have cataract surgery. Hence, 350 eyes on 201 dogs were included in the analyses. Among these, 84 eyes (59 dogs) developed a FW. Univariate analyses showed that the odds of FW increased with age and phacoemulsification time. Additionally, FW web was associated lens type, lens brand, and viscoelastic type. Multivariate analyses showed that when comparing lens types in combination with a particular viscoelastic, viscoelastic impacted the estimated prevalence of FW formation the most. In contrast, when the data were analyzed by lens brand, lens brand impacted prevalence more than viscoelastic type. Diabetes mellitus was not associated with FW formation. Based on the available data, intraocular lens implantation, viscoelastic type, dog age, and phacoemulsification time were associated with FW formation. Diabetes mellitus, gender, cataract stage, surgeon, intracameral injections other than viscoeleastic, and intra- and postoperative complications were not associated with FW formation.

Ocular ultrasonographic evaluation of cataractous and pseudophakic eyes in dogs

Ocular B-mode ultrasonography is one of the noninvasive, rapid diagnostic imaging techniques indicated in canine cataract patients to evaluate the posterior segment of the eye. This study was conducted on twelve eyes of dogs with a history of cataract, which were scanned under topical anesthesia. The preoperative and postoperative ultrasonographic biometry, and ultrasonographic features of the lens, intraocular lens (IOL), and posterior segment were recorded. There was a significant difference between pre- and postphacoemulsification mean value of the axial length of globe and anterior chamber depth. The normal ultrasonographic features of the 2-hydroxy-ethyl-methylacrylate IOL was observed in vitro by placing the IOL in a coupling gel bath; it appeared as a flying saucer with hyperechoic margins and a central anechoic optic area and similar findings were also observed in pseudophakic eyes. Posterior segment changes such as posterior vitreous detachment were noticed in two dogs and retinal detachment in one dog postoperatively. In conclusion, ocular B-mode ultrasonography could be used to locate the position of the IOL in canine pseudophakic eyes. Ocular ultrasound is still more a useful tool to locate the position of the IOL postoperatively, even in pseudophakic eyes with corneal edema or iris synechiae in dogs.

Progression and complications of canine cataracts for different stages of development and aetiologies.

To evaluate progression and complications of various cataract aetiologies and stages of development. In all, 447 eyes of 250 dogs with cataracts were monitored between 2012 and 2015. Breed, gender, age, vision, types of cataract, stage of cataract development (incipient, immature, mature and hypermature), complications of cataracts, ocular ultrasonography and electroretinography findings were recorded. Re-examinations were performed after a minimum of 1, 6 and 12 months. A relative rate of progression within 1 month was determined and progression was categorised as stationary, slow, moderate or rapid. Overall, 44∙7% cataracts progressed and 55∙3% remained stationary. Incipient, immature, mature and hypermature cataracts progressed in 34∙1, 72∙7, 66∙7 and 44∙6% of cases, respectively. Hereditary, congenital, diabetic, contusive trauma-related, perforating trauma-related, radiation-related, senile cataracts and cataracts secondary to concurrent ocular diseases progressed in 47∙1, 66∙7, 66∙7, 50, 44∙4, 0, 29∙9 and 48∙9% of cases, respectively. Rapid progression was identified in 13∙3% of diabetic and 4∙3% of hereditary cataracts. Complications were diagnosed in 43∙5% and occurred at any stage but more frequently the further the cataract had developed. Lens-induced uveitis was the most common complication. Diabetic, traumatic, secondary and hereditary cataracts were associated with more complications than senile cataracts. Stage of development and cataract aetiology are associated with different rates of progression and complications.

Intelligent Automatic Extraction of Canine Cataract Object with Dynamic Controlled Fuzzy C-Means based Quantization

Canine cataract is developed with aging and can cause the blindness or surgical treatment if not treated timely. Since the pet owner do not have professional knowledge nor professional equipment, there is a growing need of providing pre-diagnosis software that can extract cataract-suspicious regions from simple photographs taken by cellular phones for the sake of preventive public health. In this paper, we propose a software that is highly successful for that purpose. The proposed software uses dynamic control of FCM clusters in quantification and trapezoid membership function in fuzzy stretching in order to enhance the intensity contrast from such rough photograph input. Through experiment, the proposed system demonstrates sufficiently enough accuracy in extraction (successful in 42 out of 45 cases) with better quality comparing with previous attempt.

Comparison of several transport activities of lens epithelial cells from cataract and healthy dog

PurposeThe aim of this study is to compare the transport activities between normal and cataract lens epithelial cells.MethodsThe primary lens epithelial cells of healthy and cataract dog were transfected with the expression plasmid DNA of large T antigen from replication origin‐defective simian virus 40 (SV40), then cloned using a glass cylinder. The transport activities of glycine, cysteine, glutamate, arginine, leucine, carnitine, ascorbic acid and glutathione were investigated using two cell lines.ResultsThere was no significant difference in transport activity between the two cells lines except for glutamate. Glutamate transport activity was 20% lower in cells from cataract than healthy one.ConclusionsReduced glutamate transport activity may contribute to the pathogenesis of canine cataract.

Epidemiology and clinical presentation of canine cataracts in France: a retrospective study of 404 cases

To determine the epidemiology and the clinical presentation of cataracts in a population of dogs in France. Records of dogs affected by a cataract presented at the Ophthalmology Unit of Alfort Veterinary School during 2009-2012 were reviewed. The etiology was determined for each dog. The signalment of affected dogs, their medical history, age of onset, stage of progression, location of opacities, and ocular lesions associated were evaluated for each etiology. A total of 2739 dogs were presented at the Ophthalmology Unit from 2009 to 2012. Four hundred and four dogs (14.7%) (716 eyes) were diagnosed with a cataract. The population included 218 males (54%) and 185 females (46%). The gender was not recorded for one dog. The mean age (±SD) of all dogs affected by a cataract was 9 years (±3.9 years). Fifty-four breeds were represented. The Yorkshire Terrier was the only breed significantly overrepresented. The causes of cataracts observed were breed predisposition (28%), aging (22.8%), progressive retinal atrophy (12.4%), congenital cataract (5%), diabetes mellitus (4.7%), trauma (3.7%), uveitis (3%), and hypocalcemia (0.2%). In 20.3% of the cases, the etiology could not be determined. Ocular lesions associated with cataracts reported were lens luxation or subluxation (11.1%), glaucoma (3.7%), and retinal detachment (4.2%). In a French population of referred dogs, 14.7% were affected by a cataract. The main causes identified were breed predisposition, aging, and progressive retinal atrophy. A breed predisposition for the Yorkshire Terrier was recorded.

Extraction of Canine Cataract Object for Developing Handy Pre-diagnostic Tool with Fuzzy Stretching and ART2 Learning

Canine cataract is developed with aging and can cause the blindness or surgical treatment if not treated timely. The first observation must be made by pet owners but they do not have proper equipment and knowledge to see the abnormalities. In this paper, we propose an intelligent image processing method to extract canine cataract suspicious object from non-professional equipment such as ordinary digital camera and cellular phone photographs so that even casual owners of pet dog can make a pre-diagnosis of such a surgery-needed disease as soon as possible. The experiment shows that the proposed method is successful in most cases except the dog has similar colored hair to the color of cataract.

Mutation in heat shock transcription factor 4 associated with canine hereditary cataract

Mutation in heat shock transcription factor 4 associated with canine hereditary cataract